In the name of climate #6: are the oceans noisy? Sadly, yes

Human activity is responsible for different forms of noise pollution even in the oceans, harming marine animals that use sounds to communicate with each other, to find their bearings and escape danger - some can every perceive the presence of other animals or obstacles up to hundreds of kilometres away. This is the case with dolphins and whales, but also the smaller clown fish, that reach the coral reef where they will live out their lives thanks to the sounds made by the creatures that live there.

Humans have been able to hear the sounds of the oceans since the second half of the twentieth century. Since then many biologists have studied the impact that noises made by humans have on the creatures that live in the sea, such as those caused by ships, by certain fishing methods, oil rigs or military exercises.

The negative effects of these noises particularly affect marine mammals, such as whales and dolphins, according to an article published in Science which states that “there is clear evidence that noise compromises hearing ability and induces physiological and behavioral changes in marine animals”.

Many animals have adapted to noise pollution, whales, for example, have learned to avoid main shipping routes, but when human activities - such as military exercises - cause loud and sudden noises, marine animals can go deaf.

There are even cases where certain noises made by humans are permanent and have forced animals to abandon entire areas. This is what happened around the Broughton Archipelago in Canada where there are many salmon farms. The salmon farmers used devices that make noises that are disturbing to the seals that fed on the salmon, but that had a negative effect on the local population of killer whales, which fed on those same seals.

There are already many solutions to noise pollution in the oceans. Steve Simpson, marine biologist at the University of Exeter and one of the authors of the article published in Science told the New York Times that: “Noise is about the easiest problem to solve in the ocean. We know exactly what causes noise, we know where it is, and we know how to stop it.” Specifically, certain ships would have to slow down, navigation routes would have to be changed so as to keep them from approaching certain areas of the ocean, and the noisier propellers would have to be replaced with quieter ones that are already available on the market.

In the coming years, with the development of mining activities on the ocean floor it is likely that there will be even more noise in the seas. So far, international agreements to protect marine ecosystems have not taken noise pollution and its impact on the ocean into account. Scientists maintain that this is why the adoption of soundproofing technologies should go hand in hand with new ways of exploiting the seas.